Relay for alternating-current motors



March 4, 1952 A. J. LEWUS RELAY FOR ALTERNATING CURRENT MOTORS 2 SHEETSSl-IEET 1 Filed June 16, 1947 I N V E]! TOR.

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Patented Mar. 4, 1952 UNITED STATES PATENT OFFICE RELAY FOR ALTERNATINGPCURRENT MOTORS Alexander J. Lewus, Cicero, 111. Application June 16, 1947, Serial No, 754,823 3 Claims. (01. 200-87) The present invention relates to an electric current relay apparatus for alternating current induction motors of capacitor or split-phase type, having a starting and running windings.

The principal object of the present invention is the provision of regulating means whereby the ampere turns on relay coil may be regulated mechanically in direct proportion to the corresponding magnetic pull impressed. on relay coil.

A still further object of the present invention is the provision of a relay of the character indicated whereby the surge of amperage at the initial stage of motor operation is capable of energizing a solenoid in the relay for connecting the starting winding in the circuit, and whereby the latter winding may be cut off from the circuit as the amperage in the running winding is reduced to a normal operation and as the motor commences to run at a normal speed at full load or due to any current surge or overload impressed on the motor.

A still further object of the present invention is the provision of a relay, whereby, on closing of a switch for supplying electric current to the motor, the starting winding may become automatically connected in a circuit, and which may continue to be so connected until the motor cames up substantially to four-fifths of the normal speed, and when this has taken place the starting winding may automatically become disconnected from the circuit by the operation of the relay, from which point the running winding alone takes up the function of the operation of the motor.

A still further object of the present invention is the provision in the relay of the character indicated of adjustable means for connecting or disconnecting the contacts in the relay, to conform the same to the particular amperage of any given motor.

With the above general objects in view and others that will appear as the invention is better understood, the same consists in the novel construction; combination and arrangement of parts hereinafter more fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

In the drawings forming a part of this application and in which like designating characters refer to corresponding parts throughout the several Views;

Fig. 1 is a diagrammatical view of the circuit with which the present relay is connected;

Fig. 2 is a side elevational view of the relay, illustrating the position of parts thereof when 2 relay remains inoperative or at the stage when an electric motor is running;

Fig. 3 is a top elevational view thereof;

Fig. 4 is an end elevational view thereof;

Fig. 5 is a cross-sectional view on line 55 of Fig. 2-;

Fig. 6 is a cross-sectional view longitudinally of the relay, illustrating the position of parts thereof during the initial stage of operation of an electric motor;

Fig. 7 is a similar view, illustrating the position of parts of the relay when the solenoid thereof is further energized;

Fig. 8 is a similar view, illustrating the position of parts of the relay during the complete operation thereof; and

Fig. 9 is a diagrammatical view of another circuit with which the present relay may be employed.

Referring to the electric circuit, shown in Fig. 1, the same includes motor ID to which a pair of outside electric wires II and I2 lead and connect the same with a source of electric power. Wires II and I2 connect with switch I3. Wire Ii connects with starting winding I4. Wire I5, which hereinafter will be referred to as starting line, connects with said starting winding I4 and leads to starting line contact I6. Said starting line I5 may be connected to condenser I'I.

Outside wire I2 connects with, or forms coil I8 which encompasses solenoid core I9, and leaves the latter as running line 26, on which running winding 2| is positioned. The opposite end of said running line 20 connects with outside wire II intermediately of switch I3 and starting winding I4, at point 22. Running line 26 connects with contact supporting member 23, which supports running line contact 24.

When switch I3 is thrown on the electric circuit is completed through wires II and I2, running line 20 and running winding 2I, in consequence of which core I9 will become energized to set the relay, which forms the subject-matter of this application, in operation, for the purpose of bringing contact plate 25 towards contacts I6 and 24, and thereby bridging starting line I5 and running line 20.'

The initial surge of electric power in the circuit last hereinabove described brings into the circuit starting winding I4 for starting the motor. After the motor has been started, by the consequence of the utilization of electric load by starting winding I4, the amperage in coil I8 has been reduced to an extent to deenergize core I9 in order to release contact plate 25 from its engagement with contacts I6 and 24 for the purpose of eliminating starting winding I4 from the circuit. By that time however running winding 2! has commenced its operation and continues to run the motor.

The above described electric circuit and the relay for automatically bringing the starting winding into the circuit and to automatically cut the same out of the circuit after the running winding has commenced to operate the motor, are well known in the art. The novel features in the relay presently described reside in the construction of the relay and in the adjustable mechanism whereby the armature lever for actuating contact plate 25 may be adjusted to the particular amperage in coil I8 for energizing core I9. This adjustable mechanism, hereinafter described, permits the interchangeable use of a relay in connection with various motors of various horsepower and in connection with electric loads of various amperage.

The relay herein disclosed includes base 26 made of non-conducting material. Affixed by a pair of screws 2'! to said base 26 is leg portion 28 of contact supporting member 29, which supports contact I6 above and in a spaced relation with said base 26 and substantially in a central relation therewith. One of said screws 21 constitutes a terminal for starting line I5, by means of which the latter is clamped to the underface of said base 25.

Contact supporting member 23 upwardly extends from leg portion 30, which is afiixed-to base 26 by a pair of screws 3|, one of which forms a terminal for the end of running line 26 which leaves coil I8, while the other of said screws 3| constitutes a terminal for the continuation of said running line 20, which is nearest to running winding 2 I. The latter screw 3| clamps the end of said continuation of running line 20 to the underface of said base 26, as is clearly seen in Fig. 4. In effect therefore said leg portion 35 is a continuation of running line 20 as the same leaves coil I8.

Contact supporting member 23 extends above said base plate 26, its free upper end, which supports contact 24 being in a spaced relation with a corresponding end of contact supporting member 29, longitudinally of base 26.

Terminal plate 32 is affixed to base 26 by means of a pair of screws 33, One of said screws 33 constitutes a terminal for outside wire I2, by means of which the latter is clamped to the underface of base 26, while the other of said screws 33 constitutes a terminal for the continuation of said wire I2 which leads to coil I3. Thus, in effect said terminal plate 32 is a continuation of wire I2. Coil I8 is in effect a continuation of wire I2 and running line 20.

Longitudinally of base 26, and disposed thereabove, is contact plate 25 provided at each of its ends with contact 34, one disposed below each of contacts I6 and 24.

Positioned longitudinally of base 26 and intermediately of contact supporting members 23 and 29, is a pair of spaced pins 35 which project in an upward direction from said base 26, and which may be provided with screw heads 36 at one of their ends to engage the underface of said base 26. From the free ends of said pins 35 nuts or flanges 31 are insertable thereon for clamping said pins 35 to said base 26 whereby said pins 35 may be maintained in a rigid relation with base 26. Contact plate 25 is provided with a pair of openings 38 wherein said pins 35 are accommodated for permitting sliding of contact plate 25 to or away from contacts I6 and 24, said pins 35 guiding said contact plate 25 in its sliding movement. Coil spring 39 interposed between contact plate 25 and said nuts 31 normally urges said contact plate 25 towards contacts I6 and 24 in order that said contacts may contact with contacts 34 carried by said contact plate 25 for the purpose of bridging the gap between said contacts I6 and 24 so that starting winding I4 and starting line I5 may be brought into the electric circuit when core I9 is energized on closing switch I5 preparatory to the starting of the motor, as is apparent from Fig. 1.

Forming an integral part of the relay is the armature supporting standard 46, provided at its lower end with an integrally formed horizontal leg portion 4| which contacts base 26 and supports coil I8 and core I9. Screw 42 passed through base 26 and said leg portion 4| engages core Id and maintains coil I8, core I9, standard 46 and leg portion 4| in a mutually rigid relation and in a rigid relation with base 25. Extending from the opposite end of standard 45, and in a direction opposite from that of leg portion 4|, is plate 43 which overhangs contact plate 25. Said screw 42 is preferably made of a non-magnetic material.

From the free end of said plate 43 lip 44 extends in a downward direction toward base 26 and is at an incline, away from standard 40. The purpose of said plate 43 and lip 44 will be hereinai'ter described.

The armature which is attracted by core I3 when the same is energized includes an oblong lever 45, which extends from a wider head 46, having resulting shoulder 47 on each of its sides, which bear against the adjacent face of standard 45 and prevent the longitudinal shifting movement of lever 45 away from standard 40. Said standard 40 above the plane of the upper end of core I9 is provided with a transverse slot 48 of the length substantially corresponding to the width of lever 45, said slot 48 being wider than the thickness of said lever 45 for permitting angular shifting movement of the latter when positioned within said slot 48.

The free end of head 46 is provided with a downwardly depending flange 49, which is at an incline away from standard 40. Mixed to said flange 49 by means of a pair of screws 5!] is a tongue 5| made of a non-conducting material. Said head 45 at its end adjacent flange 49 is provided with a rectangular opening 52, which partially extends into said flange 49, for the purpose hereinafter described.

When core I9 is deenergized lever 45 and head 46 remain at an incline, with tongue 5| bearing against contact plate 25 for maintaining the same in a retracted position away from contacts I6 and 24, against the action of coil spring 39. Slot 48 is sufficiently wide for permitting shifting pivotal movement of said lever 45 within standard 46.

The means for normally maintaining lever 45 and head 45 in their shifted position, with tongue 5| bearing against contact plate 25, as seen in Fig. 2, includes screw 53 passed through lip 44 and in a threaded engagement therewith. The outer end of said screw 53 receives adjusting nut 54 in a threaded engagement with said screw 53, with washer 55 interposed between said lip 44 and nut 54; The inner end of said screw 53 is rounded as at 56, imparting to said end a semi-spherical formation. Said semi-spherical end 56 of screw 53 partly enters the inner end of tubular memher 51, the inner peripheral margin of said inner end of tubular member 51 being suitably rounded in conformity with the arc of said semi-spherical end 56 of screw 53 for providing a seat for said semi-spherical end 55 of screw 53 within said inner end of tubular member 5?. By virtue of this arrangement said inner end of tubular member 57 is swivelled upon the inner end of screw 53, permitting said tubular member 53 to make angular shifting motion with respect to said screw 53 in directions. Said inner end of tubular member is provided with flange 58.

Receivable within the opposite end of said tubular member 5'! is shaft 5%, the outer end of which is flattened for eiiecting wing the outer edges of which are outwardly flaring, and the outer transverse edge of which is arcuate. Receivable upon said shaft at is washer ti. The outward y flaring lateral edges Of said wing GB limit the shifting movement of said washer iii in the direction away from the tubular member 5?.

Interposed between said flange and washer BI is coil spring which is in an encompassing relation with said tubular member and shaft 59.

The transverse arcuate edge of wing Si] is in engagement with the transverse edge in head defined by opening Spring 62, hearing against flange 58 and washer urges shaft 59 away from screw 53 and towards the said edge in head 45, thereby maii said wing at in engagement with head and exerting pressure upon said head as for nonnally maintaining tongue El against contact plate for holding the latter in a retracted position a d away from contacts it and 2 as is seen in E 2. The aforesaid action of spring 52, shaft 59 wing 63 upon head 46 and tongue 5! maintains lever in an angularly shifted position and out of en agement with core if) when the latter is deenergised.

It is further observed that the greatest degree of pressure upon head it exerted thereon by coil spring 62, shaft 5i and wing 68 is at the time when said head :5 and lever d5 remain in an angularly shifted position, with contact plate retracted from contacts 56 and 2 as seen in Fig. 2, because in that position the angle defined by said spring shaft 55 and wing on one hand, and said head and. lever on the other, is sharper than the angle defined thereby when lever commences to shift into a horizontal position, or parallel with base as seen in Figs. 6, 7 and 8. This, for the reason that said spring 52 in the first of the above named positions tends to exert pressure upon head to a greater degree from transverse direction with relation to head 36, while in the last named position of said spring 62 with relation to head it and lever 35 the former tends to assume a position substan tially co-extensive with the longitudinal axis of lever 65, and thereby the transverse pressure thereof upon lever tends to diminish and dissipate.

Thus, the initial surge of electric power through coil it, on closing switch i3, is of suflicient intensity to energize core ii; to a degree to attract lever 45 from a comparative distance and against comparatively greater pressure of spring 52 against head :25 to elevate tongue ill for bringing contact plate 25 in contact witlrcontacts l6 and 2-41, than is required when lever 45 approaches core 19, because then the pressure of spring 62 on head 36 diminishes, as was hereinabove described.

The tension of coil spring 62 for varying the pressure thereof upon head 46 and lever 45 is capable of regulation and adjustment by means of screw 53. When said screw 5-8 is driven inwardly, on first loosening nut 5t, tubular member 5'! shifts upon shaft 59 towards washer t I, thereby decreasing the distance between flange 58 and washer GI and consequently decreasing the space within which said coil spring 62 is longitudinally confined. ihis operation will of course increase the tensioning action of spring the degree or" pressure thereof upon head li'i. Conversely, on driving screw 53 into the opposite direction, the tension of spring t2 and its pressure upon head :6 will be decreased. This regulation of the degree of tension of spring permits the employment of the same relay in connection with electric circuits of various amperages and consequent various degrees of energization of core I9.

Placed on the underiace of plate it is oblong rigid plate 63 which is in a transverse relation with said plate and by one of its edges is in contact with the adjacent as seen in Figs. 6, 'Z and 8. use e said plate $3 has an inte rally formed and downwardly depending U-shaped bend t l, the free end of which contacts and bears against the ad cent marginal portion of plate and forms a pivot on which said plate may angularly shift. Passed through said plate and the portion of said plate 63 is pin which rovided at its lower end with an integrally formed knob l t and with a rivet head 6? at its upper end. said plate 33 and plate are provided with registering apertures within which said pin is accommodated ior longitudinal shifting movement, the aperture in said plate fit being sufficiently large so as to permit the unobstructed shifting movement of said plate as will be later apparent. Interposed between knob .the body of plate 63 is coil spring which encompasses the lower end of pin 65'. Normally said spring 68 exerts tension against knob for urging plate 63 in contact with plate 3-3.

in threaded engagement with plate t3 and adjacent the free end of plate is screw 6% having an adjusting nut it. On loosening nut it screw may be driven downwardly against place for the purpose or" deflecting the same from plate 23, as indicated by dotted lines in Fig. 5. The downward s ting of plate tends to compress spring greater force to overcome the tension of said spring 68 in order to shift pin 6'5 in an upward direction when pressure is exerted upon knob Knob overhangs the inner end and remains in the path of mover as the same shifts to or away On reference to the relative nos 65 and head as illustrate it will. be seen that within shi ting movement of lever at. lever the nearest proximity of core is and -pp a horizontal position when said core it is energised lever iii is attracted thereto, that pin bears against A exerts pressure upon head it by virtue of th action of coil spring Thus, when lever 65 is in contact with core l pin 65 exerts the greatest pressure upon head 45, said head as causing the upward shifting movement of pin 65 and compressing coil spring 38. When the magnetic flux in coil 13 diminishes to a suincient degree, but notwithstanding the energize,- tion of core l9 and consequent contact with lever 45., and in spite of the action of spring 62, shaft of head 15 nt thereof 7 59 and wing 60, pin 65 will be capable of breaking the connection between core I9 and lever 45 for shifting head 46 downwardly. As said head it leaves pin 55, spring 62, shaft 59 and wing 60 will continue to shift head 46 downwardly as Well as tongue the latter shifting contact plate 25 away from contacts It and 24.

From the hereinabove description it Will be readily seen that when switch I3 is thrown on, the initial surge of electric current passing through coil is is of such great intensity as to be capable of energizing core I9 to a degree whereby core I9 is capable to attract lever 35 and overcome in succession the pressures of springs 62 and 68 as they bear against head d5 through the medium of wing 60 and pin 65, respectively. As head 16 comes in contact with knob 68 and shifts pin 65 upwardly against the tension of coil spring 58, as lever d5 approaches the horizontal position, at that very instant the action of spring 62 on head 16 diminishes, as was hereinabove described. It is noted however that the initial shifting of lever 35 towards core I9, against the tension of spring 62, shifts tongue 5| in an upward direction for permitting contact plate 25 to come in contact with contacts It and 24, even before said head 46 has come in contact with knob lit and before lever 35 has come in contact with core is. At the time starting winding I4 has completed its function and running winding 2i takes up the function of running the motor, at that very instant the flux in coil I8 diminishes to an extent so as to render the thrust of pin 65 at head it capable to break the connection between core I9 and lever 35. When that was done and head it comes out of contact with knob 6% spring 62 takes up the continuing function of shifting head 56 downwardly for shifting tongue 5i against contact plate 25 and against the tension of spring 39 for breaking the contact between contacts I5 and 24, with contact plate 25, head it and lever 45 eventually coming to a normal inoperative position illustrated in Fig. 2, which is the position when motor I6 is either at rest with switch I3 open or when the same is in a running condition by the action of running winding 2i and with starting winding it out of the electric circuit.

From the construction of the relay described it will be seen that the degrees of tension of springs 82 and 63 may be regulated by means of screws 53 and 69, respectively. The regulation and adjustment of the tension of said springs will adopt the relay for employment with various amperages of the electric circuit and consequently with various motor horsepowers. When the amperage in the electric circuit is greater the attraction and contact between core I9 and lever d5 will be proportionately greater, and hence in order to break the connection therebetween the degree of tension in springs I52 and 88 must be greater. Hence the mechanism for regulating and adjusting the tension of said springs as was hereinabove described.

If desired the relay may be enclosed within a suitable housing of non-conducting material and then the entire assembly may be affixed within an electric motor. When the relay is used with any given motor as a permanent fixture thereof, the adjustment of tension in springs 62 and 68 should of course be first made in said springs to conform to the particular amperage used in a given motor.

While the circuit shown in Fig. 1 has the relay in series with starting and running windings,

8 Fig. 9 illustrates another exemplification of a cir cuit in which relay coil I8 is in series with the running winding only. In that latter figure the outside wire I2 connects with one of the terminals 3i in the terminal plate 38. Connecting with other terminal 3I is the continuation of said wire I2, which leads to and connects with one end of coil l8. Connected with the opposite end of coil I8 is running line 20 having running winding 2|, and which connects with the other outside wire I I at 22. Starting line I5, having starting winding It connects at point 22 with said wire I I and line 20. The opposite end of said starting line I5 connects with terminal plate 28. Otherwise the operation of the relay, although reversed, is identical with that in Fig. 1. When switch I3 is thrown on, the initial surge of current passes through wires II and I2, running line 20, running winding 2i, terminal plate 30, and coil I8 to energize core I9. Core I9 attracts armature 45 which brings contact plate 25 in contact with contacts I6 and 2 3. This establishes the circuit through starting winding It, starting line l5, terminal plate 28, contact supporting members 23 and 29, contact plate 25, and outside wires II and I2, setting starting winding I4 in operation,

until the load therein is reduced, core I9 is deenergized to release contact plate 25 from contacts It and 2 i, and the running winding 2| takes up the function of the running of the motor.

Whereas in the circuit shown in Fig. 1 wire I2 was connected to two terminals 33 in terminal plate 32, in the circuit illustrated in Fig. 9 said wire i2 connects with terminals 3! in terminal plate 36. While in the circuit shown in Fig 1 line 25 connected with terminals 3| in the terminal plate 38, in Fig. 9 said line 29 connects with terminals 33 in terminal plate 32. In both circuits starting line 15 is connected to terminal 21 in plate 28, and contact I6.

The relay herein disclosed, adopted for use in connection with the alternating current motors, may be used in connection with a variety of circuits, as shown by two examples thereof illustrated in Figs. 1 and 9, and may be employed in connection with other electrical devices, using either a current coil or a potential coil. The relay herin disclosed is characterized by its compressed spring snap action due to springs 62 and 63 for compressing the armature.

While there is described herein a preferred embodiment of the present invention, it is nevertheless to be understood that minor changes may be made therein without departing from the spirit and scope of the invention as claimed.

What I claim as new is:

l. A relay of the class described comprising a base, a bracket mounted on said base, said bracket having an upright member, a foot at right angles to said upright member, said foot being mounted on said base, an arm having a free end and being at right angles to said upright member and on the opposite side of the upright member from the foot, and a downturned lip on the free end of said arm, an electromagnet mounted on said foot, an armature pivotally mounted in said upright member and extending transversely thereof with one end suspended above the electromagnet and the other below said arm, a pair of contacts mounted on said base, means actuated by said armature for bridging said contacts as said armature is attracted by the electromagnet on energization of the latter, a screw having a rounded end threadably mounted in the lip, a telescoping spring-biased plunger having arcuate members on each end thereof, one of said arcuate members being pivotally mounted on the rounded end of said screw and the other member bearing against the armature, and a spring-pressed pin mounted in said arm adjacent the upright member, said pin resiliently bearing against said armature with increasing degree of compression as the armature is attracted to the electromagnet, the tension of said spring-biased plunger upon said armature decreasing as the armature is attracted by the electromagnet.

2. A relay comprising an electromagnet, a bracket, an armature mounted on said bracket, a pair of electrical contacts, means actuable by said armature for bridging said contacts as said armature is attracted by said electromagnet, and a biased tensioning device pivotally mounted on said bracket, said tensioning device being in position to bear against said armature to cause the armature to swing away from the magnet when said magnet is deenergized and in position to bear substantially lengthwise of the armature when said magnet is energized.

3. A relay comprising an electromagnet, a bracket, an armature mounted on said bracket, a pair of electrical contacts, means actuable by said armature for bridging said contacts as said armature is attracted by said electromagnet, a biased tensioning device pivotally mounted on said bracket, said tensioning device being in position to bear against said armature to cause the armature to swing away from the magnet when said magnet is deenergized and in position to bear substantially lengthwise of the armature when said magnet is energized, and a second tensioning device mounted on said bracket, said second tensioning device being in position to bear against said armature under tension when said magnet is energized and to be free of the armature when the magnet is deenergized.

ALEXANDER J. LEWUS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 887,612 Everest May 12, 1908 897,812 Bendmann Sept. 1, 1908 1,032,345 Roome July 9, 1912 1,886,895 Meyers Nov. 8, 1932 1,921,127 Hutt Aug. 8, 1933 2,064,632 Schmitt Dec. 15, 1936 2,205,252 Graham June 8, 1940 2,320,252 Vaughan May 25, 1943 2,374,017 Inglehart et al Apr. 17, 1945 2,377,137 Eaton May 29, 1945 2,380,442 Immel et a1 July 31, 1945 2,402,838 Obszarny June 25, 1946 2,432,899 Immel Dec. 16, 1947 FOREIGN PATENTS Number Country Date 442,561 Great Britain Feb. 11, 1936 

